Tank fabrication system

ABSTRACT

A system and method of fabricating tanks comprising a plurality of carriages mounted on tracks and supporting tank sections and a chain drive mechanism for forcing the tanks into contacting relationship. Also included is a hydraulic ram for applying further contacting pressure so that intimate contact is established between adjacent sections. If the sections are supplied with the flanges, flanges are forced within the flange receiving portions of adjacent sections. The carriages contain provision forcing the tank section to assume a more perfectly circular, cross-section and for rotating the entire assembly after it is structurally joined by a series of tack welds. The final seam weld is made with an automatic welder over the entire circumference of the joint between each adjacent section as the tank is rotated.

as United States Paten 1 [111 3,7343? Sannipoli [4 May 22, 1973 [54]TANK FABRICATION SYSTEM FOREIGN PATENTS OR APPLICATIONS [75] Inventor:Alfred L. Sannipoli, Escondido, 1,955,761 11/1968 Germany ..228/48Calif.

Primary Examiner-J. Spencer Overholser [73] Assignee. giyicggifipufactunng, Inc., Escon- Assistant Examiner ROb6n J- CraigAttorney-Carl R. Brown and Neil F. Martin [22] Filed: May 18, 1971 [21]Appl. No.: 144,532 [57] ABSTRACT A system and method of fabricatingtanks comprising a plurality of carriages mounted on tracks and sup-[52] US. Cl. ..228/6, 29/484, 228/44, porting tank Sections and a chaindrive mechanism for 228/48 forcing the tanks into contactingrelationship. Also in- [51] [11L Cl. ..B23k 5/00 eluded is a hydraulicram for applying further contact [58] Fleld of Search ..29/484; 113/120QA; ing pressure so that intimate Contact is established 228/6, 48;219/62, 6, 59 between adjacent sections. If the sections are suppliedwith the flanges, flanges are forced within the flange References Citedreceiving portions of adjacent sections. The carriages contain provisionforcing the tank section to assume a UNITED STATES PATENTS moreperfectly circular, cross-section and for rotating 3,634,648 1 1972Morris et al. ..228/48 x th entire ass m ly after it is structurallyjoined by a 3,480,158 11/1969 Pandjuris et al... ..214/1 series of tackwelds. The final seam weld is made with 2,944,449 7/1960 Wheeler et a1.228/6 an automatic welder over the entire circumference of 2,758,367 956Dougherty 228/48 X the joint between each adjacent section as the tankis 2,753,826 7/1956 Dougherty ..113 59 mm 1,907,702 5/1933 Anderson...228/48 X 1,740,033 12/1929 Pinckney ..228/48 X 1 Claim, 9 DrawingFigures Patented May 22, 1973 5 Sheets-Sheet 1 INVENTOR. ALFRED L.SANNIPOU BY 6 g m I b ATTORNEYS Patented May 22, 1973 3 Sheets-Sheet 2INVENTOR. ALFRED L. SANNIPOLI I02 BY [8mm 84 ATTORNEYS Patented May 22,1973 3 Sheets-Sheet 3 Fig.5b

Fig.5c

u., R 0 8 HM Y P W M SOu m. L m T D E A m L@ A Fig. 5d

TANK FABRICATION SYSTEM BACKGROUND OF THE INVENTION Multiplerequirements exist for storage tanks for the storage of fluids andgases, such as petroleum products, either in underground storage orabove ground. In addition, there are requirements for mobile tanks, suchas on over the road vehicles, for carrying a wide variety of fluidsincluding molasses, water and many other gaseous or liquid consumables.Frequently these tanks are of such a size that the expense of theirshipment from a central production facility is prohibitively high. Thusit is necessary to produce such tanks at a location relatively close tothe location of eventual use. The tanks can then be made up of sectionswhich are of sufficiently small size to make over the road shipmentpractical.

The conventional fabrication technique for these tanks has been to rolla sheet into a shell of generally circular configuration and weld thetwo opposing ends. The sheets are normally obtained with flange andflange receiving portions on their opposite sides and in the finalconfiguration the tank is comprised of a plurality of these rolledsections inserted one in the other and then welded to form a leak prooftank. However, the formation of these tank sections by the process ofrolling flat sheets is subject to irregularities and the resultingsections are normally slightly out of round. As a consequence it is verydifficult to force the adjacent sections to fit, one within the other.In prior art systems a first section is placed on a horizontal surfaceand a second section lowered onto the first, whereupon the opposingsections are man-handled, with a lever like device, similar to a crowbar, so as to expand the flange over the flange receiving portion. Thisprocess is extremely time consuming, and leads to the poor utilizationof materials, since some of the sections are so malformed as to beunusable by this technique. Further, after the sections are forcedtogether it is then necessary to move the tank structure, tack welded toretain its configuration, to a separate seam welding facility. There, anautomatic welding device is utilized to make the finished welds.

Thus it would be desirable if a more efficient fabrication system couldbe designed, to reduce the man hours and the number of operationsassociated with the fabrication of tanks.

SUMMARY OF THE INVENTION In an exemplary embodiment of the invention thetanks are formed by a process and apparatus which effects the efficientproduction of tank structures.

The system of the invention utilizes guide means comprising two paralleltracks. The tracks support a plurality of carriages as a means formoving and supporting tank sections. One carriage is utilized for eachtank section necessary to produce a tank of the desired length. Thecarriages support circularizing and supporting members, which arearranged to be capable of forming two opposed semi-circular sectionshaving an inside radius corresponding to the outside diameter of thetank being fabricated. Tank sections, made by the rolling and weldingprocess, are placed on the carriages. Upper segments are forced by powermeans into their semi-circular configuration and thereby the tanksections are forced to assume a more perfectly circular configuration.

There is a means for moving and holding said section in contactconsisting of an endless chain mounted beneath the track structure andis engageable with a member extending from a movable end carriagelocated on the tracks. With the end carriage engaging the chain, and thechain being driven, the carriage will be forced to move in the samedirection as the upper surface of the chain. The end .carriage carriesan end stop and a means for supporting the end plate as well as ahydraulic ram. Opposite the stop carriage is a fixed stop which is alsoadapted to support an end plate.

When the chain is driven to force the movable end stop into engagementwith the first; tank section, the sections are forced progressivelyalong the track until they reach the fixed stop. The chain is thenstopped and the hydraulic ram actuated, to force the successive sectionsinto. intimate contact, and to force the flange of one section into theflange receiving portion of the succeeding section ifthe sections are soprovided. This contact and nesting of the successive sections is madepossible by the circularizing action of the craddling means which haveforced the sections to assume a configuration which is sufficientlyclose to a perfect circle to ensure that adjacent sections will fit onewithin the other.

When'all the sections have been moved into correct position, a series oftack welds are made by, for example, a hand welder, at spaced intervalsaround the periphery of the tank sections. In addition, tack welds aremade between the end plates and the tank sections to form a completetank. It is then possible to remove ram pressure and back off themovable end stop. The upper semi-circular members are released and meanson the carriages actuated to raise the sections out of engagement withthe lower semi-circular members.

Each carriage is provided with a plurality of rollers which contact andforce the sections to the raised position to make it rotatable. One ormore of the rollers, on one or more of the carriages, is powered so asto make it possible to drive the entire tank into rotation. The rate ofrotation is variable and is utilized to controllably rotate .the tankunder the head of an automatic welding machine to produce a continuousseam weld around the periphery of the tank, at all of the tank joints.

It is therefore an object of the present invention to provide a new andimproved tank fabrication system.

It is another object of the invention to provide a new and improved tankfabrication method.

It is another object of the invention to provide a new and improved tankfabrication system which reduces the manual labor necessary for theproduction of tanks.

It is another object of the invention to provide a new and improved tankfabrication system which provides the structure for combining all tankfabrication operations at one location.

It is another object of the invention to provide a new and improved tankfabrication system which makes it possible for all of the tank sectionsmaking up a tank to be brought into their final configuration in asingle operation.

It is another object of the invention to provide a new and improved tankfabrication system which enables all of the operations to be performedon the tank being fabricated while that tank is in a horizontalorientation.

It is another object of the invention to provide a new and improved tankfabrication system which makes it possible to utilize tank sectionswhich are sufficiently out of round to cause their rejection by othermethods.

Other objects and many attendant advantages will be apparent from areading of the following detailed description together with theaccompanying drawings in which like reference numerals refer to likeparts throughout and in which:

FIG. 1 is a side elevational view of the tank fabrication system of theinvention.

FIG. 2 is a top view partially broken away to illustrate the positioningof the roller and track mechanisms.

FIG. 3 is a sectional view taken along lines 3-3 of FIG. 1.

FIG. 4 is a sectional view similar to that in FIG. 3 but showing themechanism in position for welding.

FIGS. 5a through 5d illustrate the steps in the method of fabricatingtanks according to the invention.

FIG. 6 illustrates a tank fabricated in accordance with the invention.

Referring now to FIGS. 1 through 4 of the drawing, there is illustratedan exemplary embodiment of the invention. The figures illustrate a tankfabrication system indicated generally by the numeral 10 and including aplurality of carriages 12 supported on tracks 18 and carrying aplurality of generally circular tank sections 14. The tanks are arrangedin axial alignment by virtue of their placement on the carriages and thetracks and therefore are also in axial alignment with end plates 20 and22 carried by the movable stop means 16 and the fixed stop means 24respectively. The entire structure is carried on a concrete base 19.

The carriages utilized are sized for the particular tank section beingfabricated. Each carriage is supported on front and rear pairs of trackengaging wheels 44 and 46. The lower frame member 26 is secured to thewheels supporting flanges 45 and 47 and has a generally semicircularupper surface 2'7. Opposed to the surface 27 is the upper semi-circularsection 28 which comprises a plurality of sections 30, 32 and 34 so thatthe upper semi-circular section may be broken down for installation ofthe tank sections and for the welding operation to be describedhereinafter. The broken down operation is best illustrated in FIG. 4.The two halves of the semi-circular section are maintained in anabutting relationship with a fork member 33 receiving the end portion ofarm 32. Prior to locking the tank section in place the arm 32 is rotatedso as to bring hole 51 into alignment with hole 53 and a pin (not shown)inserted therethrough to hold arm 32 in alignment with the remainder ofthe segment 34. This configuration provides clearance for the weldingarm 107 and also makes removal of the tank sections after weldingeasier. If desired, or required by the weight of the semi-circularsections, the arm 32 may be hydraulically actuated between its retractedposition, illustrated in FIG. 4, and the extended position illustratedin FIG. 3.

As can best be seen in FIG. 1, each carriage 12 has a plurality of thepairs of semi-circular members and therefore provides support andcircularizing efforts for both ends of the sections. The opposite endsof the carriage are interconnected by beam members 70 and 71.

The upper segments are forced into the semi-circular configuration ofFIG. 3 by hydraulic cylinders 40 and 42. The cylinder 40 is mounted atits lower end by pivot 52 and its upper end by pivot 48. When hydraulicpressure forces extension of the cylinders piston rod 43 the segment isforced towards the closed position of FIG. 3 by pivoting about pivot 38.Similarly, cylinder 42 is mounted at its lower end by pivot 54 and atits upper end by pivot 50. When hydraulic pressure forces the extensionof piston rod 45 the segment 30 is forced towards its position in FIG. 3by pivoting about pivot 36.

FIG. 1 shows four tank sections that are installed in the craddles ofthe invention and are therefore more perfectly rounded than in theoriginally formed condition, as will be more fully describedhereinafter. The apparatus of the invention that forces the sections inthis condition into intimate contact as illustrated in FIG. 2 includesthe carriage 16 utilizing wheel pairs 62 and 64 to support a hydraulicram 58 mounted on frame 60. The hydraulic ram carries an end platesupporting flange and stop member 56 which is movable axially of thetank sections under the influence of hydraulic pressure delivered to thecylinder 58 by hydraulic lines (not shown). The carriage 16 is initiallypositioned through the use of the chain 68 which is driven by a sourceof power (not shown) to successively engage the end plate with the firsttank section and then with succeeding tank sections. The carriage isdrawn by the chain due to the chain engaging member 66 which dependsvertically from the frame 60 into engagement with the chain. Whenmovement of the chain becomes blocked by contact of the last section andthe supporting flange 72 of stop member 24, the hydraulic ram is broughtinto action to compress the sections to the configuration illustrated inFIG. 2.

With the tank sections properly oriented a plurality of tack welds aremade around the periphery of each joint between adjacent tack sectionsand/or the end plates. These tack welds are of sufficiently closespacing, for example 18 inches, to obtain sufficient strength to makethe structure self-sustaining. When the structure has been madeself-sustaining it is ready for finish welding. At this point the uppersemi-circular member is released and pins removed from the holes 51 and53.

The structure for raising the tack welded tank to position for finalwelding is best illustrated in FIGS. 3 and 4 and includes a pair ofhydraulic cylinders 86 and 88 pivotally mounted on bearings 92 andrespectively. The output shaft of these cylinders is connected to leverarms 102 and 104 by bearings 96 and 94. The lever arms are mounted forpivoting movement on bearings 82 and 94 and pivot between the positionsillustrated in FIG. 3, where the rollers 78 and 80, mounted on bearings90 and 100, are out of contact with the tank sections surface to aposition illustrated in FIG. 4, where the rollers have been forced intoengagement with the tank sections surface, and have caused an elevationof the tank sections raising the tank section out of contact with thelower semi-circular section.

With the tank raised to the position illustrated in FIG. 4, it is freeto rotate, and may be caused to rotate by driving in rotation one ormore of the rollers 78 or 80. These rollers may be driven by, forexample, a variable speed motor (not shown). Thus it is possible torotate the joint of the weld underneath the welding head 106 supportedon extendable arm 107 comprising an outboard section 108 and an inboardsection 1 10. Vertical support is provided by column 112.

The operation of the system and method of the invention is bestvisualized by reference to FIGS. 5a through 5d. Tank sectionsillustrated by the three representative sections 14 are made up inadvance by a process involving the successive rolling of flat sheetsuntil the formerly opposed ends of the sheets are in contact, or nearlyin contact, whereupon the opposed ends are joined by welding. It is mostexpeditious, when practicing the invention, to utilize flat sheets thatalready have flanges and flange receiving portions. The flat sheets maybe singly flanged such as the sheet making up the tank section 120 inFIG. 5a which has a single flange 122 or double flanged as illustratedin the tank section of FIG. 5a, referred to by numeral 124, whichincludes flanges 126 and 128. By utilizing double flanged flat sheets itis possible to incorporate end plates and 22 which have flange receivingportions only.

The pre-fabricated shells or tank sections are then loaded onto asufficient number of carts, placed on the tracks 18. In the caseillustrated, three carts are employed to carry three tank sections.After the sections are loaded on the carts, the upper semi-circularmembers are forced to the position illustrated in FIG. 5a. This involvesfirst extending the foldable arm 32, to align it with arm 34, and tohold the arm in position with a pin through holes 51 and 53 so that thearm assumes a configuration generally opposite to that of arm 30. Thehydraulic cylinders 40 and 42 at then actuated so as to force the uppersegment into contact with the upper surface of the tank section andcause it to assume the configuration of the arms themselves, that iscircular in total effect. Thus any irregularity present in thefabricated tank sections is compensated for the pressure maintained onthe sections by the hydraulic cylinders. The hydraulic cylinders aremaintained in their activated state while the end plate 20 is advancedon carriage 16 under the influence of the chain 68 so as to contact andengage flange 128 in particular, and tank section 14 in general, and toforce that section into are adjacent section until the last sectioncontacts end plate 22, whereupon the drive to the chain would bediscontinued, and the chain locked in position.

The final configuration of the tank is first achieved in the positionillustrated in FIG. 5b, where the hydraulic ram 58 has been actuated toextend the flange 56 carrying the end plate 20 and force that end plateover the flange 128 and to force the successive flanges into the flangereceiving portions of the adjacent tank section or end plate.

Hydraulic pressure is maintained on the ram 58 to hold the tank in itsfinal configuration while a series of tack welds are made around theperiphery of each joint so as to assure the security of theconfiguration.

The carriage 16 carrying the hydraulic ram may then be backed away,after releasing of the hydraulic pressure and the retraction of theflange. Additionally, the upper semi-circular members may be releasedfrom their circular restraint function to retract into the positionshown. in FIG. 4. whereupon, the automatic welder may be brought intoposition over each joint and the roller actuating cylinder activated toraise the tank from the lower semi-circular members and into a rotatableposition where it is in contact only with the rollers. The motor, orother device for rotating the tank, is activated and the joints rotatedunder the automatic welder which is turned on to make the continuousseam weld. The weld requires no backing plate because of the utilizationof the flange configuration which ensures that each joint will be backedby a solid piece of metal and thereby eliminate the requirement for abacking plate.

The welding process continues as the automatic welder is moved tosuccessive joints until a continuous seam weld has been made around theentire periphery of each joint. The tank is then in its final completedconfiguration and is ready for installation.

Having described my invention, 1 now claim.

1. A tank fabrication system comprising,

guide means for maintaining a plurality of approximately circular tanksections in approximate axial alignment,

first means for forcing each of said sections to assume a substantiallycircular cross sectional configuration,

second means for moving and holding said sections in contact,

third means for securing each of said sections to the adjacent section,

said guide means comprising track means for receiving supportingcarriage means, supporting carriage means for supporting said sectionsand having said first means mounted thereon,

said second means comprising stop means for limiting the movement ofsaid carriage on said guide means,

one of said stop means being engageable with mechanical means for movingsaid sections into contact,

said mechanical means comprising an endless chain mounted below saidcarriage and said stop means and engaging said chain for moving saidsections into contact. contact.

1. A tank fabrication system comprising, guide means for maintaining aplurality of approximately circular tank sections in approximate axialalignment, first means for forcing each of said sections to assume asubstantially circular cross sectional configuration, second means formoving and holding said sections in contact, third means for securingeach of said sections to the adjacent section, said guide meanscomprising track means for receiving supporting carriage means,supporting carriage means for supporting said sections and having saidfirst means mounted thereon, said second means comprising stop means forlimitiNg the movement of said carriage on said guide means, one of saidstop means being engageable with mechanical means for moving saidsections into contact, said mechanical means comprising an endless chainmounted below said carriage and said stop means and engaging said chainfor moving said sections into contact. contact.